Load-limiting clutch



' June 14,1927.

1,632,539 R. CHILTON LOAD LIMITING CLUTCH 2 Sheets-Sheet 1 Filed May 5,1926 June 14,1927.

R. CHILTON- Low LIMITING CLUTCH Filed May 5, 1926, 2 Sheets-Sheet 2 Ymvmfoh Fall/V0 C'lV/ZT/V I %m' 9% V ATTORNEY 40 tion.

Patented June 14, 1927.

[UNITED STAT ES I 1,632,539. PATENT OFFICE.

7 ROLAND cHIL'roN, or KEYPORT, NE W JERSEY, ASSIGNOR r HEALEY-AEROMABINEBUS comramr, me, A conromrron or NEW, YORK.

Loan-LIMITING CLUTCH.

' Application filed May 1926. Serial No. 106,905.

This invention relates to load-limiting friction clutches having meanswhereby the driving load reacts in opposition to a preset frictionpressure spring to release the clutch 5 at a preset load, in spiteof'wide variations in the condition of the friction surfaces. In suchclutches, a driving and driven member .are inter-connected for slightrelative movement as the load overcomes the'spring, and

, one ofthe principal objects of this invention isto provide simple andfrictionless means for th s purpose.

Due to the natural deflection of the parts under varying loads,appreciable movement 16 of the interconnecting means occurs in vclutches of this type, and one of the ob ects produce axial pressurechanges between clutch members having screw thread interso connections.Such constructions are apt to be insensitive except to load incrementssufficiently great to initiate sliding at the friction surfaces.

7 Another' object of the invention is to p50 vlde a frictionless meanswhereby the 'etion producing the drive transmitting pressures areimposed upon a common s ring means without imposing bearing 10 s betweenactuated' parts subject to relative mo- Other objects are toobtainrelatively eat capacity in a compact mechanism havmg the frictionpressures evenly distributed over a large area and to provide a simpleand rugge construct-ion adapted ,to withstand high loads with a minimumof deflection and to provide a light structure, especially with regardto. the flywheel effect of the drivenelements.

Another object of the invention is to prolowin spring pressure should bea small proportion of the drive reaction component, or in other words,that the organlzation be such that the preset load from the spring shall(when at rest) impose a friction pressure greatly in excess of that atwhich slippage is to occur. In the specific showing this is accomplishedby using a heavy spring ca-' pable of supporting a multiplied reactionfrom the driving load, and a frictionless and balanced means forimposing'such multiple reaction, comprise one of the features of thisinvention, which may alternatively be used to apply a multiphed frictionproducing pressure from a light sprin subject to smaller reactions fromthe oad. Mu1ti-- plied friction effect from the spring ressure 15obtained inthe showing byt o well known multiple-disc construction ofthe clutch. a

Various other ob'ects and advantages of the invention will e in partobvious from an inspectiomof the accompanying drawings and a carefulconsideration of the folparticular description and claims embo ing myinvention.

In t e drawings Figure 1 is a vertical section of one form of theinvention.

Figure 2 is a cross sectional view taken on the line 2 of Fig. 1 aslooking in the direction indicated by the arrow.

Figure3 is a-vertical section of-the preferred form of the invention. r

Figure 4 is an end view of Fig. 3 as lookme ing from the left hand sideand s' portions broken away for the sake ofclearness.

In the present instance and with reference to Figs. and 2m particular,10 designates the driving them er for the clutch vide a reversibleload-limiting clutch that which is rotatably supported in a bearing willbe equally effective for either direction of rotation without change inadjustment or disposition and wherein the driving and 55 driven membersmay interchange functions.

11 and drivably connected toa driving member12.

' The driven member 13 of the clutch is supported in the clutch drivingmember 10 in a manner as to permit'of relative rotation between thesemembers and has a plurality of splines 14.

Drivably engaged with the splines 14 are a multiplicity of frictiondisks 15 and alternating therewith are a number of similar disks 16 notengaged with the splines 14 but having connection with the bolts 17.

The friction disks 15, 16 are held between a pair of relatively heavyend plates 18, 19 which normally impose frictional driving pressure dueto the action of a plurality of springs 20 which tend to draw theseplates together.

The springs 20 are settable by the adjusting nuts 26 and provide themeans by which the disks 15, 16 are held in frictional drivingengagement up to any predetermined or desired amount of driving torqueas will be more fully described hereinafter.

Upon the inner circumference of the clutch driving member 10 there isformed in equally spaced relation a plurality of pockets 21 havingsymmetrically sloping sides, and somewhat similar pockets 22, 23 areformed on the inner sides of each of the end plates 18, 19. The relativedepth of the pockets 21, 22 and 23 should be such as to permit a ball 24being retained therein without offering any restraint to the frictionproducing pressure of the end plates 18, 19 upon the disks 15, 16, whenthe clutch is free from driving load. The end plates 18, 19 are mountedso as to permit them to have a certain limited rotational movementwithin the clutch member 10.

In operation of the clutch under a normal load, the disks 15, 16 areheld in frictional engagement with one another by the pres sure of thesprings 20. The balls 24 transmit motion from the clutch driving member10 to the end plates 18, 19 by means of the recesses or inclined pockets21,22, 23, and to the disks 16 by means of the bolts 17. The disks 16transmit the drive in turn to the disks 15 which are splined to thedriven clutch member 13, said member 13 being drivably connected to ameans to be driven such as a gear 25.

As a load is encountered which is in excess of the spring setting, theballs 24 will force the end plates 18, 19 apart due to the combinedaction of the balls against the sloping sides of the pockets 21, 22, 23and relieve the friction producing pressure on the disks 15, 16, thuspermitting relative motion therebetween. As the overload is relieved theballs will againmove to the. bottom of the pockets and permit the endplates to bear fully against the friction disks.

With reference to the preferred form shown in Figs. 3 and 4, 10designates the clutch driving member, 13 the driven clutch member. Tothe member 13 there are connected by means of the splines 14 a pluralitysaid notches so as to retain the bolts in any set position. The disks 16alternate with the disks 15 and are connected to the bolts 17.

In this particular form of clutch two adjacently disposed rows of balls24' and 24 are employed which are retained in conically formed pockets22 and 23 but the mode of operating remains substantially the same as inthe form first described. This preferred form is especially adapted forlarge driving capacity-because the loads are distributed over a largenumber of discs and balls, whilst the conical form of ball pocket isadapted to easy manufacture.

Having thus described my invention, I claim,-

1. In apparatus of the class described the combination of, a pluralityof driving and driven friction clutch members, a spring adapted tonormally press said members into frictional driving contact, opposedinclined faces on a pair of said driving friction members, a drivingmember having inclined faces, and rolling means constitutin the drivingmeans from the driving member to the driving clutch members and adaptedto exert a separating tendency therebetween.

2. In apparatus of the class described the combination of a pair ofaxially separable members, clutch disks therebetween, a spring adaptedto maintain said disks in frictional driving contact, anti-frictionmeans adapted to transmit drive directly to each of said.

members and to impose a separatin force therebetween proportional to theriving load and tending to release said frictional driving contact.

3. In a frictional clutch having a drive member, the combination of apair of pressure members, friction clutch members therebetween, a presetspring adapted to axially press all of said members together,anti-friction driving means between each pressure member and the drivemember adapted to impose a separating reaction between said pressuremembers.

4. In a clutch, an axially floating assemblage of clutch elements havingend members, spring means adapted to impose equal and opposite frictioncontact pressures on the end members of said assemblage, andanti-friction driving means engaging each end member, and adapted toimpose equal and opposite separating pressure therebetween.

'5. A friction clutch comprising in combination, an axially floatingassemblage of clutch members includin end members having opposedinclined riving surfaces, 9. spring adapted to press the memberstogether,'. a driving member having inclined therebetween drivablsurfaces, and anti-friction driving means having rolling contact withsaid surfaces and tending to separate the clutch members when drivingload-isapplied.

6. In apparatus of the class described,

the combination of a clutch assemblage including a" pair of end members.having inclined depressions, a spring adapted to imose balancedpressures upon said end memers, a drivingmember havinginclineddepressions, and rolling contact means in said depressionscomprising the drivin connec- 3 .tion to said clutch assemblage anrfadapted to impose" separating reactions therein.

" 7. In a load limiting device, the combinationof, a pair of'frictionpressure plates, friction means therebetween, a spring means preset tonormally impose a much greater pressure than appropriate to the desiredslipping load, and anti-friction drive means between the plates adaptedto impose a relatively great reaction on each plate from the drivefinopposition to the spring pressure.

8. In a load limiting device, the combination of, a driven member, apairof end pressure plates, a plurality of clutch plates connected for relavtive axialmovement a ternately to the driven member and the end plates,a spring means for imposing axial contacting pressure on the plates, adriving member ada ted forlimited rotation relative" to the en f plates,

opposed inclined faces on the end plates and the driving member, androlling contact drive means therebetween adapted to impose axialseparation reactions between the end plates.

9. In a clutch, the combinatlon of, a driven member, a pair of endressure plates, co-acting friction drive dis alternately drivablyconnected to the driven member and to the end plates respectively,antifriction driving means engaging each of said plates and adapted toimpose separating reactions therebetween, and a pressure spring presetto resist said reaction untll an overload occurs. 1

10. In apparatus of the class described, I

the combination of, a driving means,a pair of axially separable drivingclutch members, driven means frictionally engaged thereby, a springnormally effecting said engagement, and anti-friction means drivablyconnecting each clutch member to the driving means and adapted torelieve said -frictional enbf the class described,

member and alternating with ed at Keyport, in the county of Mon-- moutand State of New Jersey, this 3rd 3 day of May, A. D. 1926.

' ROLAND CHILTON.

